Fluid motor



Dec. 1 4, 1943. N. M. coUTY J 2,336,847 FLUID MOTOR Filed Dec. 24, 19414 Sheets-Sheet l 5T.: fr

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a I28 k m ATTORY Dec. 14, 1943. N, M COU-ry v 2,336,847

FLUID MOTOR Filed Dec. 24, 1941 4 Sheets-Sheet 2 T 7 Z* `l *:UE

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Dec. I4, 1943. v -N, M COUTY' 2,336,847

FLUID MOTOR INVENTOR ATTORNY Dec. 14, 1943,

N. M. COUTY -FLUID MOTOR Filed Dec. 24, 1941v 4 Sheets-Sheet 4 INVENTORATTORNEY V Patented ec. 14, 1943 FLUID MOTOR Norman M. Couty, ShipBottom, N. J., assignor to The Flex-O-Tube Qompany, a corporation ofDelaware Application December 24, 1941, Serial No. 424,243

(Cl. 12l 151) 3 Claims.

This invention relates to uid motors and to a control system forregulating the reciprocation of the movable member of the motor by areversing valve which is mechanically independent of the movable memberbut controlled in accordance with the position of said movable member.

It is an object of this invention to improve the art of duid pressuremotors.

Another object of the invention is to control the reversing of theprincipal movable member of a iiuid pressure motor by a floatingreversing Valve which is controlled in turn by the said principalmovable member but is mechanically independent thereof.

A further object of the invention is to control the stopping of themotor by shutting off an exhaust passage to prevent a change ofpossession of the floating valve and thus to stop the principal movablemember at one end of its travel in its cylinder.

Other objects, features and advantages will become apparent from thefollowing description and appended claims.

For the purpose of illustrating the genus f the invention, a typicalembodiment thereof is illustrated in the accompanying drawings in Figs.1 to 6, inclusive, and the operation of the said illustrative embodimentof the invention is diagrammatically illustrated in Figs. 7 to 11inclusive of the said drawings.

In the drawings:

Fig. 1 is a vertical longitudinal sectional view taken substantiallyalong the line I I of Fig. 3 centrally through a hydraulic cylinder, areversing valve cylinder and a discharge passage of a hydraulic cylinderbody.

Figs. 2, 3, and 6 are transverse vertical sectional vlews through thehydraulic cylinder body taken substantially alo-ng the lines 2 2, 3 3, 55 and 6 5 of Fig. 1.

Fig. 4 is a horizontal longitudinal sectional view taken substantiallyalong the line 3 4 of Fig. 2.

Figs. 7 to 11 inclusive are more or less diagrammatic Vertical sectionalviews of a theoretical embodiment of uid motors embodying the principleof the construction shown in Figs. 1 to 6 inclusive, and depictingespecially the relationship of the power piston within its .cylinderwith respect to its reversing valve in various operative positions ofthe iiuid motor.

Referring to the drawings, and rst-to Figs. 1, 2 and 3, a cylinder bodyI4 is provided with a cylinder bore I5 extending longitudinally of thebody Ill, a reversing valve cylinder bore I6 and a pair of bores Il andISiorming discharge and intake passages, respectively, the latter boresalso being disposed axially parallel with the reversing valve bore I6and the cylinder bore I5. A power piston -2 is disposed-in the hydrauliccylinder l5 for reciprocation therein and is provided with a pistonshaft 2| which projects througha cylinder end bearing 22, a gasketelement 23, and a packing nut 24 threaded to the cylinder body lli formaintaining the bearing 22 and gasket element 23 tightly assembled tothe cylinder body I 4 to guide the piston shaft 2l and to preventleakage by the said piston shaft 2l. The reversing valve 25 is disposedin itsl cylinder bore l5 and comprises fourr spaced pistons 25, 2l, 2Band i 29 which are made integral with or rigidly xed relative to acommon shaft 35. The nut 3I is threaded to the cylinder body I4 at theopen end of valve bore I6 for closing the latter. An annular valve guide32 split along the line 33 is disposed in the valve bore I 6 about thevalve shaft and is tightly maintained in the` position indicated in Fig.1 by means of a set screw plug 3ft.

Referring also to Fig. 4, it is noted that the open ends of thedischarge bore Il and of the intake bore I8 are threaded for thereception of standard pipe tting elements 35 and 35 for the discharge orreturn and supply of pressure uid from and to the motor. The tting 36and associated conduit 39 .extend to any suitable source of fluid underpressure. As indicated in Figs. l, 2 and Ll, a pair of bores 3l and 38extend downwardly from the top of the. cylinder body I 4 to the end ofthe hydraulic cylinder I5, thesek bores making an angle of approximately69 degrees with respect to the axis of cylinder bore l5. The bores 31and 38 extend through the intake bore I3 as indicated in Fig. 4,downwardly through the valve bore I6 to the ends of the hydrauliccylinder I5 as shown in Fig. l. With the reversing valve 25 in theposition indicated in Fig. 1, the passage 38 is open through the valve"cylinder I5 between the pistons 28 and 29 of valve 25 While piston 26of the valve 25 closes ,the bore 37 through the valve cylinder I5, butthe lower end of the bore 3l is open between the power cylinder i5 andthe Valve cylinder I3 permitting discharge of uid from the powercylinder through the valve cylinder I6.

When the valve 25 is at the other end of its cylinder I6, the left-handend as viewed in Fig. 1 the piston 29 of valve 25 cuts oi the passage 33through the cylinder I5 but leaves the lower end of the passage 33 openbetween power cylinder l5 and valve cylinder I6 while the bore 3l isopen through the Valve cylinder I6 between the pisor the other of thecenter of travel of piston 22 so that the bore 4I will register with anannular groove 43 at the left-hand' end of piston 26 when the piston isin the right-hand position shown in Fig. 1, and so that the bore 42 willregister with asimilar annular groove 44. at the right.- hand end of thepiston 28 when thejlatter is at the limit ofits travel at Vtheleft-handendof vthe hydraulic cylinder I5.

As indicated in Fig. 5, the annular groove 43 at the left-hand end ofpiston 22 not only registers with the intake bore 4| but also registerswith a discharge bore 45 which leads from the hydrauliccylinder I5 tothe discharge passage |1, but. the discharge bore 45 does notcommunicate with the reversing Vvalve I6.' As indicated in Fig. 4, adischarge bore 45, similar tothe bore 45 is Vprovided in the sametransverse' plane with the intake bore`42 so asto register with theannular groove dat the right-hand Yend. of piston 2B when the latter isat its left-hand limit of travel within the hydraulic cylinder .l5 andthe passage lit communicates between the hydraulic cylinder l5 and thedischarge passage |11 withoutcom-k munication with the reversing valvecylinder l5. A needle valve 41 is threadedto the cylinder body |11 inaxial alignment with -the bore 45 so as to close communication throughsuch bore in order to prevent the reversing movement of thereversingvalve and thereby stop operation of the piston 20 whenthe va1ve25 is atthe. left-hand end of its lcylinder it and with the piston 20 in thepositionl indicated in Fig. 1.:

Referring-now toiFigs. 1, 2 and 4, bores 5t and 5| are provided inthelcylinder body I4 and extend downwardlyin a vertical directionkfrom-the top thereof and communicate .between the discharge passage |1and the left and right-hand ends of the reversing valve cylinder |5.,The piston 29 ofV the. reversing valve 25` is adapted to close thepassage 5| when the reversing valve 25 is in the position indicatedinFig. 1.,. and. piston 2t. of the reversing valve 25 closes; the passage5|) when thereversing valve 25 is at the lefthandY end of its cylinderI6. Plugs 52 threaded to theV cylinder body I4 close the upper ends ofYthe bores 31, 38, III;l 42, 46', Eiland 5|. A small diameteredweep bore53 leads from pistony shaft 2| through the bearing22 to an annulargroove 54 in the periphery of the bearing 22, and this annular grooveregisters with a slightly inclined bore 55 which leads to the dischargebore 5|.

Figs. 1 to 11 inclusive diagrammatically depict a theoretical embodimentin which the various parts are given'nurnerals. 100 higher than thecorresponding parts in the practical embodiment shown in Figs. i1 to 6inclusive. Theoperation of the embodiment shown in Figs. 1 to 6. will beexplainedV in connection with the diagrammatic illustration depicted inFigs.`7 to 11 inclusive.

VIn Figs. '1 to 11 inclusive, the intake passages |31, |38, |41 and |42have associated therewith thearrows I indicating intakelpassages whilethe discharge passagesY If, |41, |5|and |58 have associated therewiththe arrows D indicating discharge passages.- Figs. 1 and .'1illustrate'the power piston |22 at the right-hand end of the'`r powercylinder ||5 with the angular groove |43 in the power piston broughtinto registry with the intake passage |4| and with the discharge passage|45. The needle valve |41 is assumed to be open at this time. The splitbearing |32 for the reversing valve |25 not only serves as a bearing butalso as a stationary partition interposed between the pistons |21 and|28 shown in Fig. 7. The provision of the annular groove at the lefthandend of the power piston allows relief of pressure within the chamberslying between the piston |21 and the split bearing |32 while the intakepassage |42 is cut oir by the power piston so that at this time nopressure relief is aiiorded within thechamber lying between the splitbearing' |32 and the piston |28. This causes the reversing valve |25 tobe moved to the right-hand position indicated in Fig. .'1 since anypressure in the chamber lying between the piston |26 and |21 wouldimpress equal forces on opposed end faces of such pistons and would thuscounterbalance each other while the same conditions would exist in anychamber provided between the pistons |28 and |29.

When pressure is relieved in the chamber to the left of the splitbearing |32, the chamber immediately to the right of such split bearingwould force the reversing valve |25 to the righthand position shown.With the parts in this position, the intake passage |38 is open to theright-hand end of the power cylinder i i5 to move the power piston |26to the left, the piston |253 of the'reversing valve |25 cutting olii thepassage |5| to prevent discharge from the right-hand end of the powercylinder. The piston |26 of the reversing valve at this time cuts oirthe upper end of the intake passage |31 and the reversing valvecylinder, but the lower end of the passage |31 is open between theleft-hand end of the power cylinder, and the left-hand end of thereversing valve cylinder permitting discharge from the power cylinder||5 to the discharge passage |52 to relieve pressure to the left of thepower cylinder |28 during the left-hand stroke of the power piston. l

As indicated in Fig. 8 the reversing valve |25 remains at rest duringthe left-hand stroke of the power piston since both intake passages miand M2 are out ofiV by the. piston |23 so that pressure within thechambers to the right or left of the split bearing |52 equalize eachother while pressures within the chambers between the pistons |26 and|21 or between the pistons |23 and |29 exert equal forces on opposedpiston end faces so that there is no tendency to dislodge the reversingvalve |25 from the position indicated in Fig. 7 or 8.

When the power piston |26 arrives at the lefthand end of the hydrauliccylinder as indicated in Fig. 9, the annular groove IM at the righthandend of piston |20 registerswith the intake passage |42 at dischargepassage l-4 relieving pressure within they chamber between the splitbearing |32 and piston |23v while the intake passage is cut oi by the.Ypower piston 2li/so that the chamber immediately.` to the left of theVsplit bearing |32 maintains its ypressure 'tofforce the reversing valve|25. to the letti-hand 'end of its cylinder IIB to the vpositionindicated'in Fig. 10.

With the reversingvalve V|25 in'the position shown in Fig. 10, theintake" passage 2131; admits pressure fluid tor the `lef'tof the powerpiston |23 since-the pistonljt no longer cuts Voil the intake passage|31;but rather 'does cutoi the 'dischargel passar-e150 tolprevent reliefof pressurey at the left-hand end of the power cylinder, while at thesame time the piston |29 of reversing valve |25 cuts off the intakepassage 33 at cylinder i le but permits passage through the lower end ofthe bore |38 and communication between the righthand end of the powercylinder and the discharge passage |5| to the right-hand end of thereversing valve cylinder H5 relieving pressure to the right of the powerpiston |29. This causes righthand movement of the piston |23 asindicated in Fig. 1l. As the power piston |25 moves from the positionindicated in Fig. 10 to the position shown in Fig. 11, so the po-wercylinder |25 cuts off both intake passages Ml and |132 thus equalizingpressure within the chambers to the right and left of the split bearing|32 while pressure within the chambers lying between pistons |26 and |21and between pistons |28 and |29 apply to equal areas and opposed facesof such pistons and thus counterbalance each other. This permits thevalve |25 to remain in the position shown in Fig. l1 until the annulargroove |43 again registers with the intake passage 14| to cause areversal of the valve |25 to the position indicated in Fig. '7.

If at any time the needle valve |41 of the embodiment shown in Figs. '7to 11 is screwed down to its seat closing the discharge passage |135,operation of the motor can continue only until the reversing valve |25reaches the left-hand position as indicated in Fig. 11 and the powerpiston I2@ moves to the right-hand end ofthe power cylinder H5, theposition of the power pistons in Figs. 1 and 7, at which time theannular groove |43 of Fig. 11 could no longer relieve the pressure inthe chamber immediately to the left of the split bearing |32 so that thereversing valve |25 could not be moved to the right and operation of themotor woul-d stop. Speed control may be obtained by throttling theintake flow.

As many changes may be made in the above indicated construction, andmany apparently widely different embodiments of this invention could behad without departing from the spirit and scope thereof, it is intendedthat all matter contained in the above description or shown in theaccompanying drawings shall be interpreted as il lustrative and not in alimiting sense.

What is claimed is:

1. In combination with a hydraulic cylinder, y

a power piston therein, means for introducing fluid under pressureselectively upon either side of said power piston, said means comprisinga source of pressure fluid and members defining passages from saidsource of pressure fluid to points within said cylinder on either sideof said power piston, valve means comprising a cylinder and a pair ofspaced pistons for alternately opening one and closing another of saidpassages, a pair of passages leading from said source to said valvecylinder and to the cylinder for said power piston independently of thefirst mentioned passages, said valve means including a second pair ofspaced pistons, and a stationary partition disposed in said valvecylinder intermediate said last-named pistons on said valveforseparating said pair of passages one from another, said pair ofpassages being so arranged that said power piston at each limit of itstravel opens one of such passages while keeping the other passage closedto cause pressure iiuid impressed on the valve and on said partition bysaid first passage to operate the valve and reverse the direction oftravel of the power piston.

2. In combination with a hydraulic cylinder, a power piston therein,means for introducing fiuid under pressure selectively upon either sideof piston, said means comprising a source of pressure fluid ,and membersdefining passages from said source of pressure fluid to points within.said cylinder on either side of said power piston, valve meanscomprising a shaft and a pair of spaced pistons one xed to each end ofsaid valve shaft, a second pair of pistons fixed in spaced relation onsaid valve shaft intermediate said first-named pistons, said first-namedpair of pistons being arranged for alternately opening one and closinganother of said passages, a valve cylinder for said valve means, a splitbearing arranged within said valve cylinder about said valve shaft andfixed to the cylinder intermediate the second-named pair of pistonsfixed to the valve shaft, and a pair of passages leading from saidsource to the valve cylinder and to said power piston, said splitbearing separating passages of said pair within the valve cylinder, saidpair of passages being so arranged that said power piston at each limitof its travel opens one of said pair of passages while keeping the otherclosed to cause pressure fluid impressed on the valve and on said splitbearing from said closed passage to operate the valve and reverse thedirection of travel of the power piston.

3. In combination with a hydraulic cylinder, a power piston therein,means for introducing fluid under pressure selectively upon either sideof said piston, said means comprising a source of pressure fluid andmembers defining passages from said source of pressure fluid to pointswithin said cylinder on either side of said power piston, valve meanscomprising a shaft and a pair of spaced pistons one fixed to each end ofsaid valve shaft, a second pair of pistons fixed, in

spaced relation on said valve shaft intermediate said first-namedpistons, said first-named pair of pistons being arranged for alternatelyopening one and closing another of said passages, a valve cylinder forsaid valve means, a split bearing arranged within said valve cylinderabout said valve shaft and xed to the cylinder intermediate thesecond-named pair of pistons fixed to the valve shaft, a pair ofpassages leading from said source to the valve cylinder and to saidpower piston, said split bearing separating passages of said pair withinthe valve cylinder, said pairof passages being so arranged that saidpower piston at each limit of its travel opens one 0f said pair ofpassages while keeping the other closed to cause pressure fluidimpressed o-n the valve and on said split bearing from said closedpassage to operate the valve and reverse the direction of travel of thepower piston, and other means for closing one passage of said pair ofpassages to stop operation of said piston.

NORMAN M. CQUTY.

